include_c "string.h";
use "sequence_queries.g";
use "iterator_models.g";
use "pair.g";

fun main() -> int@ {
  let A1 = "3141593";
  let A2 = "3142857";
  let N = strlen(A1);

  let result = mismatch(A1, A1 + N, A2);

  if (result.first - A1 != 3)
    return -1;
  if (not (*(result.first) == '1' and *(result.second) == '2'))
    return -1;

  return 0;
}